/Engine/Source/Editor/DataLayerEditor/Public/DataLayer/DataLayerEditorSubsystem.h
Add the actors to the DataLayer
true if at least one actor was added to the DataLayer. false is returned if all the actors already belonged to the DataLayer.
bool AddActorsToDataLayer ( const [TArray](API\Runtime\Core\Containers\TArray)< [AActor](API\Runtime\Engine\GameFramework\AActor) * > & Actors, [UDataLayerInstance](API\Runtime\Engine\WorldPartition\DataLayer\UDataLayerInstance) * DataLayer )